SQL Set Operators Traditional Set Operators: Union Compatibility: Requirement for the traditional set operators. Strong requirement. - Same number of columns. - Each corresponding column is compatible. - Positional correspondence. Apply to similar tables by removing columns first. SQL UNION Example: Example 1: Retrieve basic data about all university people. SELECT FacNo AS PerNo, FacFirstName ...
SQL Set Operators Traditional Set Operators: Union Compatibility: Requirement for the traditional set operators. Strong requirement. - Same number of columns. - Each corresponding column is compatible. - Positional correspondence. Apply to similar tables by removing columns first. SQL UNION Example: Example 1: Retrieve basic data about all university people. SELECT FacNo AS PerNo, FacFirstName ...